The Fifteenth Amendment, ratified on February 3, 1870, was an attempt to bar states from using race as a factor in deciding whether or not to allow citizens the right to vote. "Previous condition of servitude" refers to former slaves.

Section 1. The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color or previous condition of servitude.

Section 2. The Congress shall have power to enforce this article by appropriate legislation.